Pyridyl dicyanoalkanes and process



*- r 2, .75 Patented Jan. 13, 1959 control the reaction. After all of the 3-(4-pyridyl)butyronitrile has been added, the mixture is stirred for about 2,868,795 another one-half to one hour. Then about 89 grams YRID KQNES (one mole) of 2-chloropropionitrile is added in small P YL DICYANOAL AND PROCESS 5 portions. The reaction mixture is mechanically stirred Francis E. Cislak, Indianapolis, Ind., assignor to Reilly during the addition of the chloropropionitrile; the stirring Tar & Chemical Corporation, Indianapolis, Ind., a c0ris continued for from six to twelve hours after all the 119mmm of Indiana chloropropionitrile has been added. The 1,5-dicyano-3- N0 Drawing Application February 17, 1958 (4-pyridyl)pentane formed during the reaction period is Serial 715,531 lsolated 1n any suitable manner.

One Way of isolating the 1,5-dicyano-3-(4-pyridyl) 7Claim5- pentane is as follows: The ammonia is evaporated.

- Methanol and then water are added to decompose any unreacted sodamide; the reaction mixture is kept cold This invention relates to dicyanopyridylalkanes and to (0 C.) during the decomposition to prevent hydrolysis the process of making them. More particularly it relates f h 1,5-di -3 (4- id 1) Th 4- i 1i e t0 dicyanopyfidylalkanes having the following g neral is added and the mixture thoroughly agitated. Upon formula: settling, two layers are formed, a caustic aqueous layer (GHzhCHCN and the 4-picoline layer containing the 1,5-dicyano-3-( l- R I pyr1dyl)pentane. Some of the caustic aqueous layer 1s 0TH also dissolved in the 4-picoline layer; this is neutralized as N (C mCN with carbon dioxide. The 4-,picoline, any unreacted 3-(4- pyridyl)butyronitrile, and the 1,5-dicyano-3-(4-pyri- Wherem R and R are hydrogen or lower alkyl and n 15 dyl)pentane are separated from each other by fractional a small Integer Selected from 1 to distillation under vacuum, the 1,5-dicyano-3-(4-pyri- In general, the compounds of my lnventlon may be dyl)pentane distilling over above about 150 C. at prepared by reacting sodamlde wlth a pyndlne having as 1 subsmufant (C H2)n'CN and thfm'reactmg The reaction in liquid ammonia may be carried out at the resultmg sod1opy r1dine with a chloroalkylnltrlle. The atmospheric pressure or it may be Conducted at Super equation below depicts the formation of 1,5-d1cyano-3- 3O atmospheric pressures Commercially, I prefer to use,

(4PyndYDPemane: superatmospheric pressures in the order of 100-200 lbs/sq. in.

While I prefer to use liquid ammonia as my reaction medium, I can use other media such as dimethylaniline, diethylether, or the like.

EXAMPLE 2 H HC-CHaCHzCN H 1,6-dic an0-3- 2- rid l Iexa NC-CHfiOHr-C-CHaCHzCN y py y )l ne /CHZCH2CH2CN N E N CHzCHzCN Some of my dicyanopyridylalkanes may be prepared by The procedure of Example 1 is repeated except that the condensation of a Z-picoline or a 4-picoline with in Place Of the -Py l' y I use one H1016 acrylonitrile in the presence of an alkali metal catalyst. of 3-(2pyridyl)butyronitrile and in place of the 2-chloro- The equation below portrays the formation of 1,5-dicyan propionitrile I use one mole of 3-ch1oro-butyronitrile. 3-(2-pyr1dyl)pentane: EXAMPLE 3 5 +H2C=CHCN Na CHQCHRCN 1,5-dlcyan0-3-(2,5-ethylpyrldyl)pentane CH: C N N CzHs CHgCHzCN /CH2CH2ON My invention will be described more fully in conjunc- N tlon with the following specific examples. CH2CH2CN EXAMPLE 1 The procedure of Example 1 is followed with the ex- 1,5-dicyan0-3-(4-pyridyl) pentane ception that in place of the 3-(4-pyridyl)butyronitrile, I

H use one mole of 3-(2,5-ethylpyridyl)butyronitrile. NC-CH2CH2-CCH2CH2CN EXAMPLE 4 1,5-dicyano-3-(Z-pyridyl) pentane N CHZCHZCN Thirty-nine grams (one mole) of finely divided sod- Q amide, prepared in any suitable manner, are dispersed in N 2,000 cc. of liquid ammonia. To this dispersion of CHZCHZGN sodamide in liquid ammonia is added about 146 grams The procedure of Example 1 is followed with the ex- (one mole) of 3-(4-pyridyl)butyronitrile. The latter ception that in place of the 3-(4-pyridyl)butyronitrile, I compound is added in small portions to more readily use one mole of 3-(Z-pyridyl)butyronitrile.

1,7-dicyano-4- (4-pyridyl) heptane The procedure of Example 1 is'followed with the exception that in place of the 3-(4-pyridyl)butyronitrile, I use one mole of 4-(4-pyridyl)pentanonitrile and in place of the Z-chloropropionitrile I use one mole of 3-chlorobutyronitrile. I

EXAMPLE 7 1,5-dicyano-3- (4-2,6-dimethylpyridyl) pentane The procedure of Example 1 is repeated except thatin place of the 3-(4-pyridyl)butyronitrile, I use one mole of 3- (4-2,6-dimethylpyridyl) butyronitrile.

EXAMPLE 8 1,4-dicyan-2-(Z-pyridyl) butane CHzON The procedure of Example 1 is followed with the exception that in place of the 3-(4-pyridyl)butyronitrile, I use one mole of 2-(2-pyridyl)propionitrile.

The dicyanopyridylalkanes of my invention are difunctional aliphatic nitriles. They have the chemical properties associated with the 'nitriles and are capable of entering into the same type of reaction as do other aliphatic nitriles, within the limitations imposed by the pyridine nucleus. They are soluble in dilute mineral acids and possess a low volatility. A solution of about of my dicyanopyridylalkanes in high boiling coal tar bases is a useful inhibitor for the pickling of steel with aqueous nonoxidizing inorganic acids.

Of the many reactions possible with my dicyanopyridylalkanes, those of most commercial significance are the hydrolysis to pyridine dicarboxylic acids and the hydrogenation to pyridine diamines.

Heating the dicyanopyridylalkanes with aqueous caustic converts the nitrile groups to carboxyl groups:

These-pyridine dicarboxylicacids are homologs'of the pyridine dicarboxylic acids described and claimed in my U. S. Patent No. 2,7,63;658 vissuedSeptember 18, 1956.

' They may be used inzplace .of the acids of the above mentioned patent.

Catalytic hydrogenation of my dicyanopyridylalkanes converts the nitrile groups to methylamino groups:

These pyridyldiamines are useful curing agents forepoxy resins. They are also. useful in the preparation of synthetic fibers of the linear polyamide type, commonly referred to as ,nylons. By; the use of a small percentage (3%.to 10%) ofthese-pyridine diamines in the molecular make-upvof. thepolyamide resin, the dyeing properties are greatly enhanced. ,The presenceof. the pyridine ring nitrogen furnishes a point of attachment for acidudyes, thereby enabling the fibers to be dyed in the usual manner.

I claim as my invention:

1. Compounds of the class consisting of dicyanopyridylalkanes havingthe following general formula:

cinnamon wherein R and R are selected from the group consisting of hydrogen and lower alkyl and n is a small integer selected from 1 to 4 inclusive.

2. The compound 1,5-dicyano-3-(2-pyridyl)pentane. 3.1The;compo,und 1,,S-dicyano-3-(4-pyridyl)pentane. v 4; The :compound 1,-5 dicyano 3 (2,5-ethylpyri dyl)pentane.

:5; The compound. .1,5-rdicyano-3-(3-pyridyl)pentane. 6. The compound 1,5-dicyano-3-(4 2,6 dimethylpyridyl)pentane.

7. The process of preparing compounds of the class consisting of dicyanopyridylalkanes. having the following general formula:

(CH2) nCHzcN (CH2) ON No references cited. 

1. COMPOUNDS OF THE CLASS CONSISTING OF DICYANOPYRIDYLALKANES HAVING THE FOLLOWING GENERAL FORMULA: 